Interface Expert Knocks iPad Apps for Inconsistent Usability

The iPad has been hailed as an interface triumph. But one usability expert has published an exhaustive critique of the iPad, taking it to task for the inconsistency and obscurity of its apps’ interfaces.

The problem, at its core: A lack of interface standards means every app behaves in a different way.

Dr. Jakob Nielsen, hailed by some as “the king of usability,” this week published a 93-page report evaluating the iPad’s usability based on feedback from seven users who tested 34 different apps and websites. Because the iPad user interface is new and design standards have not been defined for tablet software, Nielsen argues that iPad apps currently suffer from inconsistency and poor “discoverability.”

“What did I just touch? What did I just do? The way you touch can impact what happens, and you can’t see what you just did, so it’s invisible,” Nielsen said in a phone interview with Wired.com.

Nielsen is criticizing exactly what Wired hailed a few weeks ago: The minimalist interface of the iPad. Because the interface is so sparse, that allows content to take over the entire device — a powerful attraction for content creators and consumers. But, Nielsen says, that can lead to confusion, because it’s hard to tell what you’re supposed to do with what’s onscreen.

“These things accumulate,” he added. “You can’t tell a difference — can you scroll? Will it jump? It makes it more confusing. Here’s the kicker: All these things will be stuff you can actually learn if you put your mind to it. But each application is different and that means this learning will not take place.”

Such is the consequence of abandoning old standards and starting with a clean slate. Over the last 25 years, designers have established and refined a firm set of guidelines for interface design on desktop-based platforms such as the Mac and Windows. Many of those guidelines are baked into operating systems in the form of user interface controls and functions, like scroll bars and radio buttons. But with the emergence of the nearly buttonless, multitouch iPad, Apple has unleashed a new beast.

Even Apple hasn’t seemed to have nailed a standard yet for the iPad. According to Daring Fireball blogger John Gruber, Apple scrapped some of its default iPhone software — the clock, calculator, stocks, weather and voice apps — because they didn’t look right when re-purposed for the iPad.

“Ends up that just blowing up iPhone apps to fill the iPad screen looks and feels weird, even if you use higher-resolution graphics so that nothing looks pixelated,” Gruber wrote. “It wasn’t a technical problem, it was a design problem.”

On top of that, developers of the first iPad apps did not have possession of iPads prior to launch. Thus, the majority of early iPad apps were basically coded in the dark, which is why interfaces are varying so wildly, Nielsen said.

“Apple should get some hard whacks over the head for that,” Nielsen said. “It’s not that the developers or designers can’t do it; it’s just that they weren’t allowed to do it.”

In the summary of his study, Nielsen listed examples where touching a picture caused apps to behave in five different ways: Nothing happens, the picture enlarges, the picture links to additional information, the image flips to reveal more photos, or navigation choices pop up.

Nielsen also knocked content-based iPad apps for having a “crushing print metaphor.” That is, content often lacked the basic interactivity of a web page, and for most content apps you can’t tap a headline to jump to a corresponding article.

Nielsen stressed that this was only an early study, and he’s aware designers are still devising a set of standards for iPad apps. He said the purpose of publishing his study now was to point the problems out to developers early so they can begin discussing solutions and achieve consistency.

“One reason we published this now is I don’t want months to go by with thousands of other wacky apps coming out,” Nielsen said. “I want these designers thinking, ‘Let’s worry about this now,’ so we can come to a consensus about best practices.”

Already, some iPad app developers are opining in blogs and forums about iPad design principles. For example, Marco Arment, developer of the popular iPhone and iPad app Instapaper Pro, wrote a blog post about overdoing interface metaphor — designing software to appear too similarly to the physical object it’s trying to reproduce.

The problem with that approach, Arment argued, is that nearly every limitation and frustration of the original physical object has also been reproduced. The app version of a calculator, for example, hasn’t made any significant advancements from the physical object, and in some ways the real thing is still better.

Arment explained that his “read later” app Instapaper Pro was an example of software that breaks free from metaphor. In reading mode, you can view articles that split up into easily readable “cards,” but as soon as text is selected, you can begin scrolling. In that way, it’s a combination of the experience of reading a website and a book.

Nielsen’s study did cover the dilemma developers face between cards and scrolling for reading content, echoing many of Arment’s thoughts.

“I read that Nielsen post and loved it,” Arment told Wired.com. “It confirms a lot of what I’ve been thinking with iPad interfaces.”

“Developers are particularly challenged to make touch interfaces discoverable while preserving attractiveness and minimizing clutter,” he added. “If everything touchable clearly looks like a button, we won’t win any design awards. But if everything looks pretty and features are buried by too many images and textures, a lot of our customers won’t find important functionality.”